public class Solution {

    static int commonChild(String a, String b){
        int[][] C = new int[a.length()+1][b.length()+1];

        for (int i = 0; i < a.length(); i++) {
            for (int j = 0; j < b.length(); j++) {
                if (a.charAt(i) == b.charAt(j)) {
                    C[i+1][j+1] = C[i][j] + 1;
                } else {
                    C[i+1][j+1] = Math.max(C[i+1][j], C[i][j+1]);
                }
            }
        }
        for (int i = 0; i < a.length(); i++) {
        }

        return C[a.length()][b.length()];
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String s1 = in.next();
        String s2 = in.next();
        int result = commonChild(s1, s2);
        System.out.println(result);
    }
}